Study on the removal of Escherichia coli by Electrocatalyst technology in the water
| Autor: | Ru-Huei Yan, 顏如彗 |
|---|---|
| Rok vydání: | 2014 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 102 Environmental Protection Department and Department of Health of regulations established Escherichia coli standards for various types of drinking water and water resources. People usually used reverse osmosis (RO), ozone and ultraviolet light to sterilize drinking water, which possessed different advantages and drawbacks. One of the most significant advantages is that electrocatalytic material under DC electricity will produce highly strong oxidation agents（i.e., hydroxyl radicals）. These oxidation agents can easily decompose the cell membrane, degrade organic pollutants and decrease color of wastewater. In this study, the electrocatalystic technology was applied to degrade Escherichia coli（E.coli）in the tap water and the effects of different operating conditions were evaluated. The synthetic water samples with E.coli added were used in this research. Three types of materials such as graphite, Titanium dioxide（TiO2）, Ruthenium dioxide（RuO2）was served as the anode respectively and graphite was selected as the cathode for all tests. The electrode spacing is 7 cm and different voltage gradients（i.e., 14.3, 21.4, 28.6 V cm-1）was conducted, respectively, for one-minute treatment. Results showed that the sterilization rate (99%) of TiO2 catalyst materials better than that of RuO2 and graphite under voltage 28.6 V cm-1. Under such voltage gradient, the electrocatalytic system could effectively generate hydroxyl radicals（‧OH）to react and eventually destroy the cells of E.coli. For practical application, a multiple module with TiO2 anode and graphite cathode was applied for further test. Both batch and continuous tests were conducted by using a different number of electrode plates and different electric field of 10、30 and 60 V, respectively. The best performance was the continuous mode with 60 V for 1 minute, which could remove 100% E.coli. The EC and pH maintained stably during and after the treatment. After all, this electrocatalytic module exhibits practicality and feasibility for removing E.coli in the tap water. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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